This application relates generally to backhaul networking in wireless telecommunications networks and, more particularly, to providing a temporary emergency backhaul link for a radio base station (“RBS”) over an air interface in response to an interruption or failure of a primary backhaul link of the RBS.
Protecting against backhaul link failures is a fundamental principle of telecomm networking. In a technique called dual diversity protection, two physically distinct links are used to connect two nodes of a network, so that if one of the links fails, backhaul traffic can be diverted to the other link, thus maintaining service on the network. Providing such diversity is particularly difficult in the case of cellular base stations because of the cost of installing separate links to each base station. This difficulty is exacerbated when the base stations are out-of-region (i.e., in territory where a cellular operator does not provide land-line services). In many cases, the cost of backhaul diversity is so high that diversity protection is not installed at all, leaving base stations exposed to a single point of failure.
Other diversity solutions such as microwave backhaul have been proposed. Microwave backhaul involves the installation of a separate radio system on each base station. Microwave backhaul often requires a Federal Communications Commission (“FCC”) license and often also requires frequency coordination with all other users of the microwave band in the locale surrounding a particular base station.